Replacing Defensive End Taylor Hart

The star of Oregon's 2012 recruiting class, Arik Armstead will get his moment to shine as the Ducks' starting defensive end in 2014.

Hart, the cornerstone of Oregon's defensive line last season, leaves big shoes to fill.

Arriving at Oregon as a two-sport prospect, Armstead left the basketball program to focus exclusively on football this spring.

He told Andrew Greif of The Oregonianthat placing his emphasis on football this spring paid immediate dividends:

Just being around my team more in the weight room a lot more and trying to focus on getting stronger and, you know, just being in a football mind set for longer. That helps when you’re in a football mind set, just constantly thinking about getting better at football.

Armstead should have ample opportunity to make an impact, feeding off teammates DeForest Buckner and Tony Washington.

Both Buckner and Washington had breakout 2013 campaigns, and their presences at tackle (Buckner) and blitzing outside linebacker (Washington) should give Armstead mismatch opportunities.

Replacing Wide Receiver Josh Huff

Josh Huff was the quintessential No. 1 receiver, combining big-play ability with the reliability of a possession receiver.

Dwayne Stanford was a favorite target of quarterback Marcus Mariota's in the Ducks' spring game earlier this month, catching three passes.

At 6'5", Stanford is the rangiest receiver among the team's wideouts. He combines his size with an elusiveness that should make him a reliable target on short to mid-range routes.

With Stanford looking like a possible focal point of the passing game, redshirt freshman Devon Allen appears capable of providing the big plays Oregon loses with Huff's departure.

"[Allen] being able to cut it loose and play at his track speed is starting to happen more and more, and as a result of that he's starting to make more plays," Helfrich said in April, per Matt Prehm of 247Sports.

Allen put that track speed to use in the spring, scoring on touchdown receptions of 49 and 45 yards.

Replacing Cornerback Terrance Mitchell

The starting cornerback job opposite All-American Ifo Ekpre-Olomu provides a great opportunity for a player to emerge as a playmaker.

Last season, opposing offenses opted to avoid Ekpre-Olomu as much as possible, but Terrance Mitchell made them pay with a team-high five interceptions.

Oregon needs Mitchell's successor to be equally adept at forcing turnovers to keep passing games honest.

Dior Mathis and Troy Hill are in their fifth years with the program, so their familiarity with the scheme is unrivaled. They have also had opportunities to show off their talent in reserve roles and in the team's nickel formation.

Hill forced a fumble and broke up four passes in 2013. While he later served a suspension, Mathis came on strong, helping the Ducks to wins over Oregon State and Texas.

"[Oregon State is] the best passing team in our league and you know I was ready to turn him loose," defensive backs coach John Neal told Andrew Greif of The Oregonian.

Either is capable of becoming the partner Ekpre-Olomu needs to maintain Oregon's standing as one of the most fearsome secondaries in the Pac-12.

Replacing Running Back De'Anthony Thomas

De'Anthony Thomas' multifaceted style is not easily replaced. Thomas filled so many roles in his three seasons at Oregon that it will require more than one player to replicate his production.

Sophomore Thomas Tyner appears capable of taking on the dual role Thomas manned as both a ball-carrier and receiving threat out of the backfield.

Tyner's size and running style is a fit for the role of feature back, which he will split with junior Byron Marshall.

In sharing carries with Marshall, Tyner's versatility will allow him to take on some of Thomas' duties on offense.

As far as Thomas' role on special teams, his ability to change momentum in the return game is a difficult skill to match. However, using the speed that makes him a standout on the Oregon track team, Mathis could be the solution to replacing Thomas on kick returns.